The Common Core State Standards (CCSS) for English Language Arts have at their center the notion that students should be challenged to read texts at steadily increasing complexity levels as they progress through school so that all students remain on track to handle the more advanced reading demands of college and careers. An automated measure of text complexity can help educators achieve this goal. For example, the Common Core State Standards note that more precise, more accurate, and easier-to-use tools are urgently needed to help make text complexity a vital, everyday part of classroom instruction and curriculum planning. To address this challenge, the present inventors have observed that an automated text analysis tool could help teachers accomplish key instructional objectives such as identifying texts that are within a student's zone of proximal development and helping students define reasonable learning targets.